At MS level 1, you plan long-term demand for parts that are manufactured or purchased. When level 1 is calculated, master schedule proposals create shop order requisitions or production schedules and/or purchase requisitions and/or supplier schedules and/or distribution orders. MRP breaks down only semi-manufactured and purchased components. The parts processed in MS on level 1 do not generate shop order requisitions during MRP; they are broken down and then generate a demand of semi-manufactured and purchased components.
The parts on level 1 are usually manufactured, although they can also be purchased. You do not see intermediate steps in the structure, such as blow-through parts (T parts) between the parts on level 0 (zero) and the parts on level 1. The parts do not exist physically in the intermediate steps; this is merely a grouping concept. Components of parts that were planned on level 0 are automatically entered in level 1. Forecast information comes from level 0. You can add other forecasts for these parts in level 1. A part does not need to have a level 0 to be planned in MS level 1.
Master scheduling also supports the concept of multi-site planning through the use of material transfers executed via distribution orders. Multi-site planning can be used when two or more sites interact in a single supply chain, with parts distributed to one or more demand sites from a single supplying site. Multi-site planned parts are defined as supplied from an internal supplier corresponding to the supplying site. You can perform master scheduling for a single site, or alternatively execute master scheduling for multiple sites in support of a multi-site supply chain environment. Master scheduled parts supplied from another site are defined as multi-site planned in the Supplier for Purchase Part window, indicating that the supply comes from an internal supplying site. Master scheduling plans supply proposals across these sites and generates distribution orders for the material move requirements.
While not as sophisticated as multi-site MRP, multi-site master scheduling consists of two or more sites working together in an integrated supply chain. Unlike planning networks in a multi-site MRP, you can execute master scheduling for sites one at a time, but it is up to you to manually determine the order in which master scheduling is executed, for the sites in the supply chain.
Master scheduling supports the process of generating supplier schedules. When using master scheduling in this mode the Demand Time Fence and Planning Time Fence on the MS Level 1 Part window should be set to 0 as supplier schedule template rules are applied. The parameter Create S/P Req should be set as Create S/P Req Entire Horizon.
DOP parts can be administrated by MS Level 1, and generally master scheduled DOP parts should have the parameter Gen Fixed MS in MS Level 1 Part window as Not Create MS Receipt and parameter Create S/P Req in MS Level 1 Part window should be set to Do Not Create S/P Req since the pegged supply order will be created by DOP. By selecting the Allow MRP Explosion for DOP Part check box in MS Level 1 Part window, MRP will explode through the default manufacturing structure and create proposals for non-DOP parts in the structure, based on netted MS proposals.
When the parameter Create S/P Req in MS Level 1 Part window is set to Create S/P from MRP, then MRP will create component supplies based on netted MS proposals while MS Level 1 part supply proposals will be created by MRP based on actual demand. Since MRP creates supplies for actual demand the purpose of planning time fence is redundant. Therefore when MRP creates supplies for MS handled actual demand, both demand and planning time fences can be set to an equal value.